>> >omega is the volume of the unit cell which in FCC is not alat^3 but 1/4 >of alat^3 >
OK, thank you, Stefano and Mighfar Imam. I think it is the volume of ??unit cell", not "cell" as your anwser. We also can understand it as the volume of one effective atom in the cell. Therefore, for bcc, it should be 1/2 of alat^3, is right? Jiayu ------------------------------ ------------------------------------------- Jiayu Dai Department of Physics National University of Defense Technology, Changsha, 410073, P R China -----------------------------------------
